Paul de Vivie, alias ‘Vélocio’, was the ‘father’ of French cycle touring. In the 1920s he advocated balloon tyres of up to 2.25″ (57mm) cross-section on 20″ (500mm) rims, giving an overall diameter of about 24″ (600mm).4 He reached his conclusions during a lifetime in which he cycled the equivalent of 15 times round the world ‘all of it as careful experimental touring work with a view to improving machine design and method of riding’.5

As early as 1911 he wrote:

“My own experience has gone no further than to 50 centimetre wheels furnished with 50 millimetre tyres, but I can guarantee that in an experiment extending as far as 15,000 kilometres covered, they will not have the smallest disadvantage from the point of view of their running. It simply seems to me they are more prone to skidding, but this is perhaps due to the fact that their tyres have no tread and that the bicycle is very short.”6

Vélocio died in 1930 and his obituary in the CTC Gazette7 included a photograph of him with an open-framed small-wheeler. Over the next ten years several British cycle tourists emulated his use of smaller wheels. They included A.C. Davison, Cycling magazine’s technical expert, and Medwin Clutterbuck, the CTC Consul for Sussex. Both riders used tyres of about 24″ x 1 5/8″ (600mm x 40mm). [Clutterbuck used 22″ x 1 3/8″ rims (560mm x 35mm).] Davison covered some 5,000 miles (8,100 km) on his ‘Little Wheels’ and declared it “a quite satisfactory bicycle”.8

Medwin Clutterbuck had two small-wheeled cycles built by F.W. Evans of London. On the first of these he toured the Alps, Dolomites and Norway, often on poorly paved roads. In England he covered up to 200 miles (320 km) in a day. Half a century later he still considered his second Evans-built small-wheeler “the epitome of what a touring machine should be”.9

The idea of a reduction of tyre diameter being matched by a corresponding increase in cross-sectional area certainly has merit. The volume of air and pressure remains the same as in the conventional tyre, while the wider cross-section compensates for (and can even improve on) the otherwise harsher ride of the small wheel.

As for rolling resistance, a reasonable prima facie indicator is the length of the tyre print (under a known weight) divided by the inflated tyre radius.10 For a given tyre pressure and load, the contact patch area is approximately constant, regardless of tyre diameter. (For example, a tyre inflated to 50 psi and carrying a load of 100 lbs has a contact patch with an area of approximately 100/50 square inches, ie. 2 square inches, whatever format the tyre may be.11) However, with the Vélocio approach to small wheels the patch is wider but shorter. Thus compensation is obtained for the otherwise higher rolling resistance.

However, this compensation depends on superior lightweight tyre carcass construction. This is difficult to achieve because, the larger the cross-section, the stronger the carcass must be to hold a given pressure. For economy of manufacture, the strength of wide section tyres often comes from thicker, heavier and less flexible materials, and results in a higher rolling resistance13.

Vélocio therefore advocated canvas-backed, thin, flexible carcasses produced by Edwardian English tyre manufacturers. In 1911 he bemoaned the fact that, for fear of warranty claims, such tyres were not made in France.

Apart from the warranty issues, stronger materials that enable thinner, lighter and more flexible construction cost more and there may be little demand. It is significant that Medwin Clutterbuck abandoned his small-wheelers after World War 2 because it was no longer possible to have his tyres custom made by the Constrictor company.